October 21-22, 2018

Point of Care Ultrasound UCSF Continuing Medical Education

Disclosure

I have no relevant financial relationships with any companies related to the content of this course.

Lung Ultrasound and Thoracentesis

Stephanie Conner, MD UCSF Medical Center at Parnassus Heights

3

4

Objectives

• Basic principles of lung ultrasound • Key findings with lung ultrasound • Overview of thoracentesis

5

Probe Selection

Linear10-15 MHz25 mm CurvilinearPhased Array

6

Patient Position

Chest. 2011;140(5):1332-1341. doi:10.1378/chest.11-0348

Hospitalized Patient Technique

• Interstitial findings• Anterior: A or B lines • Lateral Bases: normal to

have some B-lines

• Look for effusions

• Probe orientation• Vertical (longitudinal) • Midclavicular line !

posterior axillary line

Used with permission from Arun Nagdev

8

Findings on lung ultrasound

• Normal Lung • Alveolar and interstitial changes (pulmonary

edema, fibrosis, etc.) • Consolidation • Pleural Effusion • Pneumothorax

9

Findings, continuedA-Lines B-lines

Effusions Consolidations

Pneumothorax

10

A Lines and B Lines• Curvilinear or Phased Array Probe • Increase Gain • Depth 12-16cm

11

Normal Lung

• Normal aerated lung scatters ultrasound waves, can’t be seen

• A-lines are horizontal hyper echoic lines representing artifact: reverberations between the highly reflective pleura and transducer

12

13

A lines = non-thickened interstitial septa

14

Alveolar Interstitial Changes

• Widening of the interlobular septa allows for propagation of ultrasound waves and the formation of b-lines.

• Seen in pulmonary edema, PNA, ARDS, ILD

15

Rib RibTissue

Air/WaterInterface

“B” Lines

16Acute Interstitial Syndrome

Arise from the pleural line

Well-defined

Move with lung sliding

3 per rib space

Reach screen edgeB lines = interstitial syndrome

17

Lung US: Dynamic Monitoring

Liteplo et al. Real-time resolution of sonographic B-lines in a patient with pulmonary edema on CPAP. AJEM (2010)

• Case: Hx CHF, ESRD, dyspnea, orthopnea

• Initial US: Diffuse B-lines • After CPAP x 3.5hrs: A-lines

18

Review

A-lines vs B-lines

Curvilinear or Phased Array Which Probe?

Scan Where? Anterior Midclavicular

What are B-lines? Interstitial SyndromeCHFPNAARDS

FibrosisAre B-lines pathologic in lateral zones?NO!

A-Lines B-Lines

19

Alveolar Consolidation

• “Hepatization of lung”

• 98.5% PNAs abut pleura

• US vs CT: (Lichtenstein 2007)

• Sens: 0.91 • Spec: 0.98

20

Case: 50 y/o male with cough & fever

Liver

21

Pleural Effusion

• Identification of a hypoechoic or echo-free space surrounded by typical anatomic boundaries:

• diaphragm (and abdominal organs) • chest wall • Ribs • visceral pleura • normal/consolidated/atelectatic lung

22

PositioningStart South then Go North

23

RUQ/Perihepatic view: Normal

Morison’s Pouch

Costophrenic Recess

Diaphragm

24

Pleural Effusion

25

Pleural Effusion

• US more sensitive than XR or exam:

• Exam > 300mL • CXR >200mL • US > 20 mL

• Scan dependent zones

• Fluid is hypoechoic (black) • Large effusions generally

more symptomatic

Effusion

Lung

Liver

26

Simple vs complex effusions

27

Consolidation and Effusion Summary

• More sensitive than physical exam or X-ray • Faster to acquire than CXR • Less radiation

28

Pneumothorax

29

Probe Selection

Linear10-15 MHz25 mm Curvilinear

30

Rib

Alveoli

RibShadow

Normal Lung: Sliding Visceral Pleura

Slide used with permission of Arun Nagdev

31

Is Pleural Sliding

Present?

32

Is Pleural Sliding

Present?

Pneumothorax

33

34

SoftTissue

NormalLung Beach

Ocean

Normal M-mode of Lung

35

SoftTissue

AbnormalLung

Ocean / Barcode

Abnormal Lung M-mode: PNEUMOTHORAX

36

OVERVIEWConfirm: M-Mode

PneumothoraxNo Pneumothorax

Ocean + Beach Ocean

37

The Lung Point

• Sensitivity: 0.66• Specificity: 1.00(Lichtenstein 233 ICU pts vs CT)

38

39

US: Pneumothorax

• Outperforms CXR in supine patients • Much higher sensitivity, similar specificity • Lower specificity critically ill ICU patients • False positives with pulmonary scarring,

TB, ARDS (specificity 60-91%) • Lung Point: 100% specificity

40

Lung US Review

• A-Lines: R/O CHF. Likely COPD/PE/Normal • B-Lines: Diffuse: CHF, ARDS, PNAs. • B-Lines: Focal: PNA • Hepatization likely consolidation • Effusions: scan posterior and lateral bases. Find

the diaphragm! • Pneumothorax: absence of lung sliding, lung

point highly specific

41

Thoracentesis

42

43

US Guidance in Thoracentesis

• Find fluid on ultrasound • Establish landmarks for safe needle insertion

with adequate depth • Usually not done under direct US guidance • Check for lung sliding after the procedure

44

Safe for thoracentesis?

45

Safe for thoracentesis?